Radio-frequency system in package including antenna

ABSTRACT

A system comprising at least one antenna and a circuit, wherein the circuit is at least in part not a semiconductor chip or a die. The at least one antenna and the circuit are arranged on a package. Alternatively described is a system comprising at least one antenna and at least one circuit, wherein the at least one antenna and the at least one circuit are arranged on a package, wherein the at least one circuit performs a radio-frequency and optionally a base-band and/or a digital functionality.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority afforded by patentapplication PCT/EP2004/004851, entitled “Radio-Frequency System InPackage Including Antenna,” filed on May 6, 2004 and by patentapplication Ser. No. 11/488,107 (filed Jul. 17, 2006), which is acontinuation of application Ser. No. 11/040,622, now U.S. Pat. No.7,095,372, filed on Jan. 21, 2005, which is a continuation ofapplication no. PCT/EP02/12427, filed on Nov. 7, 2002.

BACKGROUND OF THE INVENTION

The present invention relates generally to novel integrated circuitpackages that include a new family of miniature antennas in the package.

There is a trend in the semiconductor industry towards the so-calledSystem on Chip (SoC) and System on Package (SoP) concepts. The fullintegration of systems or subsystems into a single chip, package ormodule provides many advantages in terms of cost, size, weight,consumption, performance and product design complexity. Severalelectronic components for consumer applications, such as handsets,wireless devices, personal digital assistants (PDAs) or personalcomputers (PCs) are becoming more and more integrated into SoP/SoCproducts.

The concept of integrating a miniature antenna into a package or moduleis especially attractive owing to the tremendous growth and success ofcellular and wireless systems. In particular, there is a new generationof short/medium range wireless applications such as Bluetooth™,Hyperlan, IEEE802.11 and ultra wide band (UWB), Wimax and Zig Beesystems where the progressive system integration into a single, compactproduct is becoming a key success factor (see for instance, S. Harrisand H. Johnston, “Handset Industry Debate Bluetooth™ Chip Options”,WirelessEurope, May 2002).

This concept of integrating a miniature antenna into a package or moduleis especially attractive as well in GSM, UMTS, PCS 1900, KPCS, CDMA,WCDMA, and GPS.

There have been reported several attempts to integrate an antenna in apackage or module. These designs feature two important limitations:first the operating frequency must be large enough to allow aconventional antenna to fit inside the chip; second the antennaperformance is poor in terms of gain, mainly due to the losses in thesemiconductor material. According to D. Singh, et al., the smallestfrequency in which an antenna has been integrated together with anelectronic system inside the same was 5.98 GHz. Typical gains that havebeen achieved with such designs are around −10 dBi.

In general, there is a trade-off between antenna performance andminiaturization. The fundamental limits on small antennas weretheoretically established by H. Wheeler and L. J. Chu in the middle1940's. They stated that a small antenna has a high quality factor (Q),because of the large reactive energy stored in the antenna vicinitycompared to the radiated power. Such a high quality factor yields anarrow bandwidth; in fact, the fundamental derived in such theoryimposes a maximum bandwidth given a specific size of a small antenna.Related to this phenomenon, it is also known that a small antennafeatures a large input reactance (either capacitive or inductive) thatusually has to be compensated with an external matching/loading circuitor structure. It also means that it is difficult to pack a resonantantenna into a space which is small in terms of the wavelength atresonance. Other characteristics of a small antenna are its smallradiating resistance and its low efficiency (see, R. C. Hansen,Fundamental Limitations on Antennas, Proc. IEEE, vol. 69, no. 2,February 1981).

Some antenna miniaturization techniques rely basically on the antennageometry to achieve a substantial resonant frequency reduction whilekeeping efficient radiation. For instance, patent application WO01/54225 A1 discloses a set of space-filling antenna geometries (SFC)that are suitable for this purpose. Another advantage of such SFCgeometries is that in some cases they feature a multiband response.

The dimension (D) is a commonly used parameter to mathematicallydescribe the complexity of some convoluted curves. There exist manydifferent mathematical definitions of dimension but in the presentdocument the box-counting dimension (which is well-known to thoseskilled in advanced mathematics theory) is used to characterize someembodiments (see discussion on the mathematical concept of dimension inW. E. Caswell and J. A. Yorke, “Invisible Errors in DimensionCalculations: Geometric and Systematic Effects”, Dimensions andEntropies in Chaotic Systems, G. Mayer-Kress, editor, Springer-Verlag,Berlin 1989, second edition, pp. 123-136 or K. Judd, A. I. Mees,“Estimating Dimensions with Confidence”, International Journal ofBifurcation and Chaos, 1,2 (1991) 467-470).

So-called chip-antennas are described in H. Tanidokoro, N. Konishi, E.Hirose, Y. Shinohara, H. Arai, N. Goto, “1-Wavelength Loop TypeDielectric Chip Antennas”, Antennas and Propagation SocietyInternational Symposium, 1998, IEEE, vol. 4, 1998 (“Tanidokoro, et al.”)or H. Matsushima, E. Hirose, Y. Shinohara, H. Arai, N. Golo,“Electromagnetically Coupled Dielectric Chip Antenna”, Antennas andPropagation Society International Symposium, IEEE, vol. 4, 1998. Thoseare typically single component antenna products that integrate only theantenna inside a surface-mount device. To achieve the necessarywavelength compression, those antennas are mainly constructed using highpermitivity materials such as ceramics. The drawbacks of using such highpermitivity materials are that the antenna has a very narrow bandwidth,the material introduces significant losses, and the manufacturingprocedure and materials are not compatible with most packagemanufacturing techniques; therefore they do not currently include othercomponents or electronics besides the antenna, and they are not suitablefor a FWSoC or FWSoP.

There have been recently disclosed some RF SoP configurations that alsoinclude antennas on the package. Again, most of these designs rely on aconventional microstrip, shorted patch or PIFA antenna that is suitablefor large frequencies (and therefore small wavelengths) and feature areduced gain. In K. Lim, S. Pinel, M. Davis, A. Sutono, C. Lee, D. Heo,A. Obatoynbo, J. Laskar, E. Tantzeris, R. Tummala, “RF-System-On-Package(SOP) for Wireless Communications”, IEEE Microwave Magazine, vol. 3, no.1, March 2002 (“Lim, et al.”), a SoP including an RF front-end with anintegrated antenna is described. The antenna comprises a microstrippatch backed by a cavity which is made with shorting pins and operatesat 5.8 GHz. As mentioned in Lim, et al., it is difficult to extend thosedesigns in the 1-6 GHz frequency range where most current wireless andcellular services are located, mainly due to the size of conventionalantennas at such large wavelengths. Another design for an antenna on apackage is disclosed in Y. P. Zhang, W. B. Li, “Integration of a PlanarInverted F Antenna on a Cavity-Down Ceramic Ball Grid Array Package”,IEEE Symp. on Antennas and Propagation, June 2002. Although the antennaoperates at the Bluetooth™ band (2.4 GHz), the IC package issubstantially large (15×15 mm) and the antenna performance is poor (gainis below −9 dBi).

Patent application EP 1126522 describes a particular double S-shapedantenna design that is mounted on a BGA package. Although no precisedata is given on the package size in the application, typically,S-shaped slot antennas resonate at a wavelength on the order of twicethe unfolded length of the S-shaped pattern. Again, this makes the wholepackage too large for typical wireless applications where the wavelengthis above 120 mm. Also, this design requires a combination with highpermitivity materials that, in turn, reduce the antenna bandwidth,increase its cost and decreases the overall antenna efficiency.

Regarding the package construction and architecture, there are severalstandard configurations depending mainly on the application. Some basicarchitectures are: single-in-line (SIL), dual-in-line (DIL),dual-in-line with surface mount technology DIL-SMT, quad-flat-package(QFP), pin grid array (PGA) and ball grid array (BGA) and small outlinepackages. Other derivatives are for instance: plastic ball grid array(PBGA), ceramic ball grid array (CBGA), tape ball grid array (TBGA),super ball grid array (SBGA), micro ball grid array BGA® and leadframepackages or modules. A description of several standard packagingarchitectures can be found on the websites of several packagemanufacturers, e.g.: www.amkor.com (see also L. Halbo, P. Ohlckers,Electronic Components, Packaging and Production, ISBN: 82-992193-2-9).

In PCT/EP02/12427 (filed as well by the applicant, but not publishedwhen this current application was filed), attempts have been made inorder to incorporate a miniature antenna to a package together with asemiconductor die.

Although this arrangement is suitable for certain applications itinvolves some disadvantages. More components in the package leads to abigger size of the system. Another reason not to have a fully integratedsolution is that some manufacturers incorporate their own processorsonto the printed circuit board (PCB) and prefer to incorporate a packageor module antenna rather than a fully integrated package. Moreover,having a circuit in the same package or module as the die itself, canincrease the amount of heat to be dissipated and might lead to anincrease of temperature of the whole system causing a malfunction of thedie. Besides, interference between the antenna and the die might occur.This could lead to a decrease in the performance of the system.

In the last few years, several improvements in packaging technology haveappeared mainly due to the development of Multichip Module (MCM)applications (see, for instance, N. Sherwani, Q. Yu, S. Badida,Introduction to Multi Chip Modules, John Wiley & Sons, 1995). Thoseconsist of an integrated circuit package that typically contains severalchips (i.e., several semiconductor dies) and discrete miniaturecomponents (biasing capacitors, resistors, inductors). Depending on thematerials and manufacturing technologies, MCM packages are classified inthree main categories: laminated (MCM-L), ceramic (MCM-C) and deposited(MCM-D). Some combinations thereof are possible as well, such as e.g.MCM-L/D and other derivations such as Matsushita ALIVH. These MCMpackaging techniques cover a wide range of materials for the substrate(for instance E-glass/epoxy, E-glass/polyimide, woven Kevlar/epoxy,s-glass/cyanate ester, quartz/polymide, thermount/HiT^(a) epoxy,thermount/polyimide, thermount/cyanate ester, PTFE, RT-Duroid 5880,Rogers RO3000® and RO4000®, polyiolefin, alumina, sapphire, quartzglass, Corning glass, beryllium oxide and even intrinsic GaAs andsilicon) and manufacturing processes (thick film, thin film, siliconthin film, polymer thin film, LTCC, HTCC).

SUMMARY OF THE INVENTION

The objective technical problem to be solved by the invention is toprovide a system with improved characteristics in view of the prior art,said device being applicable in various ways.

This problem is solved by the features of the independent claims.Further embodiments of this invention result from the dependent claims.

The present invention generally relates to novel integrated circuitpackages, modules or systems comprising a new family of miniatureantennas according to the any independent claim. Also, the inventionrelates to several novel ways of arranging the materials and componentsof the package to include the antenna. Particularly, main advantages ofthe invention are as follows:

-   -   the small size of the antenna, which allows the use of very        small packages (such as for instance chip scale packages        (“CSP”)) at typical wireless wavelengths;    -   the antenna geometry that enables such a miniaturization;    -   the arrangement of the antenna in the package;    -   the compatibility of the antenna design with virtually any state        of the art packaging architecture;    -   scaled and distributed devices can be put together in an        economical and efficient way;    -   the heating-up effect of the package can be dissipated to an        external component or an additional package, reducing the risk        of malfunction of the device;    -   several packages can be combined/put together, e.g. packages of        RF circuits and/or antennas to be e.g. maintained by a processor        to combine signals to be used in a multiple input multiple        output (MIMO) environment. This might lead to a scalability of        the packages according to the demands of the respective        environment or system.

In contrast to the chip-antennas as described in Tanidokoro, et al., thepresent invention relies on the specific novel design of the antennageometry and its ability to use the materials that are currently beingused for integrated circuit package construction, so that the cost isminimized while allowing a smooth integration with the rest of thesystem.

The objective problem is solved by a system comprising at least oneantenna and a circuit, wherein the circuit is at least in part not asilicon chip or a die. The at least one antenna and the circuit arearranged on a package.

The problem is also solved by a system comprising at least one antennaand at least one circuit, wherein the at least one antenna and the atleast one circuit are arranged on a package, wherein the at least onecircuit performs a base-band and/or a digital functionality.

This base-band functionality comprises e.g.:

-   -   Conversion from a digital bitstream to a sequence of symbols in        transmission, or symbol acquisition and digital data        regeneration in reception;    -   Clock recovery and symbol synchronization;    -   Automatic gain control;    -   Error correction algorithms;    -   Data encryption/decryption;    -   Channel estimation for adaptive detection;    -   Memory blocks (for example for temporary data storage, for        programming other digital blocks, etc.);    -   Transmission/Reception buffers for storage of received packets        and packets to be transmitted; or    -   Microprocessors and/or microcontrollers to carry out data        processing, control tasks (like data handshaking with other        chips), implement communication ports protocols (like USB) or        audio features (like an audio CODEC).

In an embodiment of the invention the (at least one) circuit comprises aradio-frequency circuit (RF-circuit). In particular, the couplingbetween the at least one antenna and the radio-frequency circuit can bea reactive coupling, in particular a capacitive or inductive coupling.

In another embodiment, the radio-frequency circuit is connected to orlocated on a ground plane.

Yet another embodiment is directed to at least some of the connectionsof the radio-frequency circuit being balanced.

In another embodiment, a radio-frequency component is arranged outsidethe package. In particular, this radio-frequency component could be amatching network. As a further option, the radio-frequency component canbe a matching network, a bypass or a through-connection.

Optionally, the radio-frequency circuit on the package can be a matchingnetwork, a bypass or a through-connection.

It is to be noted that the radio-frequency component arranged outsidethe package could be an external circuit as well as an externalsub-circuit, the latter e.g. being part of a larger circuit. Thisexternal circuit or sub-circuit can be or comprise a radio-frequencycircuit, respectively.

Furthermore, the radio-frequency component outside the package as wellas the radio-frequency circuit on the package can be a power amplifier,respectively.

Some other possibilities of components that could be part of theradio-frequency circuit (internal) or radio-frequency component(external to the package) are:

-   -   Power amplifier;    -   Low noise amplifier;    -   Filters;    -   Diplexer;    -   Local oscillators (like a quartz crystal oscillator);    -   Modulator/demodulator;    -   Switch;    -   Mixer;    -   (Signal) Detector;    -   Phase shifter; or    -   balun.

In yet another embodiment the at least one antenna is connected to theradio-frequency circuit and at least in part the radio-frequency circuitis connected to the radio-frequency component outside the package.

In an additional embodiment, the at least one antenna is connected tothe radio-frequency component outside the package directly.

Furthermore, the radio-frequency circuit can comprise a balun.Preferably, this balun can be incorporated as a printed circuit or as adiscrete component. Additionally, the balun can be placed inside thepackage or outside of the package.

In another embodiment, the ground plane is not located underneath or ontop of the at least one antenna. In particular, the projection of theantenna should not be on a ground plane.

In particular, the package can be an integrated circuit package (ICpackage).

Another embodiment is directed to a system, wherein the radio-frequencycircuit or the radio-frequency component includes at least one filter.Preferably, this filter is or comprises a band-pass characteristic.Additionally, other filter types as high-pass or low-pass filters orcombinations thereof can be provided.

A next embodiment is directed to the at least one antenna beingconnected to an input/output connector of the package and at least apart of the circuit being connected to an input/output connector of thepackage. Said connectors can be the same or different ones.

In another embodiment the at least one antenna is a space fillingantenna. Preferably, the space filling antenna has a dimension biggerthan 1.

In fact, there exist several definitions of the dimension, e.g. a boxcounting dimension and a grid dimension. Preferably, these dimensionsamount to numbers between 1 and 2, respectively, in particular thedimensions amount to 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9,2.0. The respective value depends on the miniaturization of the packetsize.

In particular, space filling is directed to the ability of filling thespace where the curve is located. This space could be an approximatedsurface or some sort of three-dimensional volume.

In general, increasing the number of segments, reducing the size of thesegments, narrowing the angles between the segments and increasing thedimension of the curve will lead to further miniaturization,respectively.

As a subsequent embodiment, the antenna can comprise a conductingpattern at least a portion of which includes a curve, wherein said curvecomprises at least five segments. Each of the at least five segmentsforming a pair of angles with each adjacent segment in said curve and atleast three of said segments are shorter than 1/10 of the longestfree-space operating wavelength of said at least one antenna.

In particular, the smaller angle of the pair of angles between adjacentsegments is less than 180° C. and at least two of said smaller anglesbetween adjacent section segments are less than 115° C., wherein atleast two of the angles, which are on the same side of the curve and areformed from adjacent segments of the group of said at least fivesegments, are different.

As a subsequent option, said conducting pattern fits inside arectangular area, the longest side of said rectangular area beingshorter than ⅕ of the longest free-space operating wavelength of said atleast one antenna.

The number of “at least five” segments can as well be in particularseven, nine, eleven, fifteen, twenty or twenty-five segments.

In another embodiment, at least the at least one antenna and/or theradio frequency circuit comprise(s) a connection with a radio-frequencyinput/output connector. In addition, the radio-frequency componentoutside the package can as well comprise such a connection with aradio-frequency input/output connector.

In particular, the at least one antenna can be a modular or a discretecomponent. As an option, the modular or discrete component can be asurface mount technique component (SMT component).

In a further embodiment, both ends of the at least one antenna can beconnected to the package, in particular to Input/Output connectors ofthe package. In a particular embodiment, both ends of the antenna areconnected to Input/Output connectors of the package.

Another embodiment is directed to the at least one antenna being aparasitic element. This parasitic element can be incorporated inside thepackage or, as an alternative, outside the package.

In yet another embodiment the system comprises at least one externalantenna.

In addition, the system can comprise a switch. This switch can be placedoutside or on the package. As a next embodiment, the switch can be usedto commute between the at least one (internal) antenna and the at leastone external antenna.

The switch can be a jumper or a bypass, or any mechanical switch withseveral positions to select manually a distinct antenna from severalavailable antennas. The switch can also be an electromechanical switch(like a relay), or an electronic switch like a transistor, FET,FLIP-FLOP or the like.

The use of a switch to select between the at least one (internal)antenna and the at least one external antenna could be used to implementan antenna diversity system. The technique of antenna diversity consistsof providing several antennas to the receiver as a way to protect thereceiver from signal fading in the communication channel. The antennasmust be arranged so that there is little, or no, correlation between thesignals received by each one of them.

In an alternative embodiment, the at least one antenna is not physicallyconnected to any other component. This might as well apply to theexternal antenna mentioned above.

Furthermore, the at least one antenna could be a balanced or anunbalanced antenna.

In addition, the at least one antenna can be loaded with discretereactive components, e.g. capacitors and/or inductors.

As another embodiment, the antenna can be loaded with external loads.

Another embodiment comprises several systems as described above, whereinthe antennas are forming a multiple antenna communication system.

This multiple antenna communication system can be amultiple-input-multiple-output system, a smart antenna system, a phasedarray system or a sensor network.

For certain applications it is advantageous as well to separate theradio frequency band from the base band, because of interferenceproblems between both parts. Higher quality components, which might needmore space could be used if one part of the signal processing circuit isplaced outside the package.

The technique of having a separate outside part of the (functional)circuit systematically opens the possibility to use existing componentsoutside the package, such as e.g. clocks, oscillators or filters.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be illustrated and explainedhereinafter on the basis of the drawings:

FIG. 1 shows an embodiment of a package including an antenna and acircuit;

FIG. 2 shows an embodiment of a package including an antenna and acircuit composed by a base band circuit;

FIG. 3 shows an embodiment of a package including a dipole antenna and aradio-frequency circuit together with an additional circuit outside thepackage;

FIG. 4 shows an embodiment of a package including a monopole antenna anda circuit, both connected to a matching network outside the package;

FIG. 5 shows an embodiment of a package including a balanced antenna anda radio-frequency circuit together with an additional circuit outsidethe package;

FIG. 6 shows an embodiment of a package including a balanced antennawith a reactive loading;

FIG. 7 shows examples of space filling curves;

FIG. 8 (FIG. 8A to FIG. 8D) shows an example of how the grid countingdimension is calculated;

FIG. 9 (FIG. 9A and FIG. 9B) shows an example of how the box countingdimension is calculated.

FIG. 10 shows an embodiment of a package including an antenna and acircuit.

FIG. 11 shows an embodiment of a package with a matching network.

FIG. 12 shows an embodiment of a package with radio-frequency componentoutside the package.

FIG. 13 shows an embodiment of a package with a power amplifier.

FIG. 14 shows an embodiment of a package with an antenna and a circuit.

FIG. 15 shows an embodiment of a package including an antenna, acircuit, and a parasitic element.

FIG. 16 shows an embodiment of a package with a second antenna externalto the package.

FIGS. 17A to 17C show embodiments of a system with an antenna and anelectrical circuit enclosed in a common package housing.

FIG. 18 shows an embodiment of a system with an antenna and anelectrical circuit enclosed in a common package housing.

FIGS. 19A and 19B show embodiments of a package with a balun.

FIG. 20 shows an embodiment of a multiple-antenna communication systemthat forms a MIMO system.

FIG. 21 shows an embodiment of a multiple-antenna communication systemthat forms a smart antenna system.

FIG. 22 shows an embodiment of a multiple-antenna communication systemthat forms a phased array system.

FIG. 23 shows an embodiment of a multiple-antenna communication systemthat forms a sensor network.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 shows an embodiment of a package 1 including an antenna 100 in anarea 101 and a circuit 130. Both, the antenna 100 and the circuit 130are arranged on a substrate 102. Preferably, there is no ground planeunderneath the antenna 100, i.e. the area 101 is free of any conductivematerial, at least in 50% of the surface above or below area 101.Particularly, the only metal that is placed below or above the antennapattern are the connectors (such as for instance wire bonds or metalstrips).

The antenna 100 is a monopole antenna with a single radiating armcomprising seven segments 111 through 117. Preferably, the side lengthof the rectangular area 101 is the longest operating wavelength for theantenna divided by five. The antenna 100 forms at least two angles suchas angle 121 and angle 122 being less than 115° C. Although notrequired, it is preferred that at least two of the angles that are lessthan 180° C. are defined in the clock-wise and counter clock-wisedirections at the opposite sides of the curve (right side for 121, leftfor 122). The antenna curve 100 is fed through a connection 105 to a padon the circuit 130, such a connection including, but not limited to, awire bond.

The circuit 130 preferably is embodied as a radio-frequency circuit (RFcircuit). The antenna 100 is connected to the RF circuit 130,transferring the unbalanced signal of the antenna 100 to the RF circuit130. The RF circuit 130 can be connected to the ground plane of theantenna 100. The RF circuit provides some RF functionality needed in anRF front-end, like e.g. antenna impedance matching,unbalanced-to-balanced transformation, power amplifying, filtering,mixing, frequency conversion, etc.

The output connection of the RF circuit 130, as represented in theembodiment can be a balanced device. Optionally, the RF circuit 130comprises a connection to a “0” level reference.

Alternatively, the output connection of the RF circuit 130 can beunbalanced. In such a case the common ground “GND” is an input signalfor the RF circuit 130.

The RF circuit 130 is connected to the monopole antenna 100 andcomprises optional connections to terminals like common ground “GND”,108 “0”, 107 “+” and/or 109 “−”.

FIG. 2 shows an embodiment of a package 2 including the antenna 100 inan area 201 and a radio-frequency circuit (RF circuit) 230 together witha base band component 240 arranged on a substrate 202.

The antenna 100 has been described in FIG. 1 above. It comprises sevensegments 111 through 117 and forms at least two angles 121 and 122 beingless than 115° C. The antenna 100 is connected to the RF circuit 230 bya connection 205.

The RF circuit 230 and the base band component 240 are connected to theground connector GND. The base band component 240 is connected to theterminals “+” 207, “0” 208 and “−” 209.

The base band component 240 provides at least some of the base bandfunctionality required in the system, like for example conversion from adigital bitstream to a sequence of symbols, symbol acquisition, digitaldata regeneration, clock recovery, symbol synchronization, automaticgain control, error correction algorithms, data encryption and/ordecryption, channel estimation for adaptive detection, analog-to-digitalconversion, etc.

The RF circuit 230 performs at least some of the RF functionality neededin an RF front-end, like for example antenna impedance matching,balanced-to-unbalanced transformation, power amplifying, filtering,mixing, frequency conversion, etc.

FIG. 3 shows an embodiment of a package 3 including a dipole antenna 300and a radio-frequency circuit 330. An external circuit 350 is locatedoutside the package 3. The dipole antenna 300 comprises two radiatingarms 303 and 304 and is fed by a differential input/output terminal 305,which is provided by a couple of close connectors such as for instancetwo wire bonds. Other suitable feeding means could include twoconducting strips placed on the same layer as the antenna, the twostrips reaching directly or by means of a via hole, the solder balls ofa flip-chip, or the pad connection region of a flip-chip connected bymeans of tape automatic bonding (TAB).

A substrate 302 can be embodied as a single layer or a multilayer, butin any case it leaves a clearance with no conducting material of atleast 50% of the area 301 where the antenna is enclosed, in any of thelayers above or below the layer on which the antenna is lying.

The antenna 300 is connected to the RF circuit 330, transferring thebalanced signal to the RF circuit 330. The RF circuit 330 can beconnected to ground. The RF circuit 330 performs at least some of the RFfunctionality needed in an RF front-end, like for example antennaimpedance matching, balanced-to-unbalanced transformation, poweramplifying, filtering, mixing, frequency conversion, etc.

The output signal 331 of the RF circuit 330 is unbalanced, andafterwards connected to an external circuit 350, which can be anexternal chip.

Alternatively, the output connection 331 of the RF circuit 330 can bebalanced. In such case, two connections to different pins (two pinsinstead of one pin 331) of the package, preferably labeled as “+” and“−” are necessary, with the option of the presence of a third pin beingthe “0” level reference.

FIG. 4 shows an embodiment of a package 4 including a (unbalanced)monopole antenna 100 (as described in FIG. 1) and an RF circuit 430,both connected to an external RF circuit 450, which is located outsidethe package 4.

A substrate 402 can be arranged as a single layer or a multilayer, butin any case it to leaves a clearance with no conducting material of atleast 50% of the area 401 where the antenna is enclosed, in any of thelayers above or below the layer on which the antenna is lying.

The antenna 100 and the RF circuit 430 are connected to at least oneInput/Output connector (which can be a pin) of the package 4,respectively, i.e. pin 431 for the antenna 100 and pin 432 for the RFcircuit 430. An interconnection between the antenna 100 and the RFcircuit 430 is provided by the external RF circuit 450, which ispreferably another RF (sub-)circuit external to the package. Preferably,the external RF circuit 450 can be a matching network, a bypass or athrough-connection.

The RF circuit 430 could also be connected to the antenna 100, henceperforming at least some RF functionality needed in an RF front-end. Theexternal RF circuit 450 provides additional RF functionality, e.g. itcould be a short circuit that establishes direct electrical contactbetween antenna 100 and RF circuit 430.

As indicated by FIG. 4, the output between the RF circuit 430 and theexternal RF circuit 450 (e.g. matching network) is unbalanced, but itcould also be balanced instead.

As an alternative, the antenna 100 could be directly connected to the RFcircuit 430, which is connected to the external RF circuit 450, whichcan optionally be a matching network.

FIG. 5 shows an embodiment of a package 5 including a balanced antenna300 (as described in FIG. 3) and a radio-frequency circuit 530 (RFcircuit). An additional circuit 550 is placed outside the package 5.

A substrate 502 can be arranged as a single layer or a multilayer, butin any case it leaves a clearance with no conducting material of atleast 50% of the area 501 where the antenna is enclosed, in any of thelayers above or below the layer on which the antenna is lying.

Both arms 303 and 304 of the antenna 300 are connected to a respectiveterminal of the package 5, i.e. arm 303 is connected to terminal 551 andarm 304 is connected to terminal 552. These terminals 551 and 552 of thepackage 5 are connected to the external circuit 550. Via terminals 531and 532 the RF circuit 530 of the package 5 is connected to the circuit550, whereas the RF circuit 530 is further connected to terminals 533and 534 of the package 5. These terminals 533 and 534 are theinput/output connectors to which an external RF front-end (not shown)can be connected.

This embodiment is similar to what has been described with FIG. 3, butthe antenna 100 being balanced. Preferably, all connections shown inFIG. 5 are balanced, although at least some of them could be unbalancedas well.

This embodiment is advantageous to be applied for an external poweramplifier (PA), because this amplifier typically is differential (i.e.balanced) in order to enable noise suppression and in order to minimizeunnecessary heating-up of the amplifier.

FIG. 6 shows an embodiment of a package 6 including a balanced antenna300 with a reactive loading 610 and 620. The antenna 300 has beendescribed in FIG. 3 above. The arm 303 is connected to a load 610 andthe arm 304 is connected to a load 620. The antenna 300 is connected viaconnection 606 (for arm 303) and connection 605 (for arm 304) with an RFcircuit 630, which is also attached to the package 6 onto the substrate602. The RF circuit 630 is connected to a terminal 632 of the package 6to which also a chip 650 is attached. Furthermore, the RF circuit 630 isconnected to a terminal 631.

The reactive loads 610 and/or 620 could be placed at the beginning ofthe conductive pattern of the antenna or, alternatively, at the end ofit. Optionally, the loads 610 and/or 620 can be placed to anyintermediate point. Moreover, the reactive loads 610 and/or 620 can beplaced outside the package if the necessary connections via terminals ofthe package 6 are provided.

This scheme of reactive loading is advantageous for furtherminiaturization purposes of the antenna.

FIG. 7 shows examples of space filling curves. Filling curves 701through 714 are examples of prior art space filling curves for antennadesigns. Other types of multiband antennas that also feature a reducedsize are multilevel antennas as disclosed in WO 01/22528, which herewithis incorporated by reference.

FIG. 8 (FIG. 8A to FIG. 8D) shows an example of how the grid dimensionis calculated.

The grid dimension of a curve may be calculated as follows: A first gridhaving square cells of length LI is positioned over the geometry of thecurve, such that the grid completely covers the curve. The number ofcells (N1) in the first grid that enclose at least a portion of thecurve are counted. Next, a second grid having square cells of length L2is similarly positioned to completely cover the geometry of the curve,and the number of cells (N2) in the second grid that enclose at least aportion of the curve are counted. In addition, the first and secondgrids should be positioned within a minimum rectangular area enclosingthe curve, such that no entire row or column on the perimeter of one ofthe grids fails to enclose at least a portion of the curve. The firstgrid preferably includes at least twenty-five cells, and the second gridpreferably includes four times the number of cells as the first grid.Thus, the length (L2) of each square cell in the second grid should beone-half the length (L1) of each square cell in the first grid. The griddimension (D_(g)) may then be calculated with the following equation:

$D_{g} = {- {\frac{{\log\left( {N\; 2} \right)} - {\log\left( {N\; 1} \right)}}{{\log\left( {L\; 2} \right)} - {\log\left( {L\; 1} \right)}}.}}$

For the purposes of this application, the term grid dimension curve isused to describe a curve geometry having a grid dimension that isgreater than one (1). The larger the grid dimension, the higher thedegree of miniaturization that may be achieved by the grid dimensioncurve in terms of an antenna operating at a specific frequency orwavelength. In addition, a grid dimension curve may, in some cases, alsomeet the requirements of a space-filling curve, as defined above.Therefore, for the purposes of this application a space-filling curve isone type of grid dimension curve.

FIG. 8A shows an example two-dimensional antenna 800 forming a griddimension curve with a grid dimension of approximately two (2). FIG. 8Bshows the antenna 800 of FIG. 8A enclosed in a first grid 801 havingthirty-two (32) square cells, each with a length L1. FIG. 8C shows thesame antenna 800 enclosed in a second grid 802 having one hundredtwenty-eight (128) square cells, each with a length L2.

The length (L1) of each square cell in the first grid 801 is twice thelength (L2) of each square cell in the second grid 802 (L2=2=L1). Anexamination of FIG. 8A and FIG. 8B reveal that at least a portion of theantenna 800 is enclosed within every square cell in both the first andsecond grids 801, 802. Therefore, the value of N1 in the above griddimension (D_(g)) equation is thirty-two (32) (i.e., the total number ofcells in the first grid 801), and the value of N2 is one hundredtwenty-eight (128) (i.e., the total number of cells in the second grid802). Using the above equation, the grid dimension of the antenna 800may be calculated as follows:

$D_{g} = {{- \frac{{\log(128)} - {\log(32)}}{{\log\left( {2 \times L\; 1} \right)} - {\log\left( {L\; 1} \right)}}} = 2}$

For a more accurate calculation of the grid dimension, the number ofsquare cells may be increased up to a maximum amount. The maximum numberof cells in a grid is dependant upon the resolution of the curve. As thenumber of cells approaches the maximum, the grid dimension calculationbecomes more accurate. If a grid having more than the maximum number ofcells is selected, however, then the accuracy of the grid dimensioncalculation begins to decrease. Typically, the maximum number of cellsin a grid is one thousand (1000).

For example, FIG. 8D shows the same antenna 800 enclosed in a third grid803 with five hundred twelve (512) square cells, each having a lengthL3. The length (L3) of the cells in the third grid 803 is one half thelength (L2) of the cells in the second grid 802, shown in FIG. 8C. Asnoted above, a portion of the antenna 800 is enclosed within everysquare cell in the second grid 802, thus the value of N for the secondgrid 802 is one hundred twenty-eight (128). An examination of FIG. 8D,however, reveals that the antenna 800 is enclosed within only fivehundred nine (509) of the five hundred twelve (512) cells of the thirdgrid 803. Therefore, the value of N for the third grid 803 is fivehundred nine (509). Using FIG. 8C and FIG. 8D, a more accurate value forthe grid dimension (D_(g)) of the antenna 800 may be calculated asfollows:

$D_{g} = {{- \frac{{\log(509)} - {\log(128)}}{{\log\left( {2 \times L\; 2} \right)} - {\log\left( {L\; 2} \right)}}} \approx 1.9915}$

FIG. 9 (FIG. 9A and FIG. 9B) shows an alternative example of how the boxcounting dimension is calculated.

The antenna comprises a conducting pattern, at least a portion of whichincludes a curve, and the curve comprises at least five segments, eachof the at least five segments forming an angle with each adjacentsegment in the curve, at least three of the segments being shorter thanone-tenth of the longest free-space operating wavelength of the antenna.Each angle between adjacent segments is less than 180° C. and at leasttwo of the angles between adjacent sections are less than 115° C., andwherein at least two of the angles are not equal. The curve fits insidea rectangular area, the longest side of the rectangular area beingshorter than one-fifth of the longest free-space operating wavelength ofthe antenna.

One of the advantages of the package arrangements of the presentinvention is that they allow a high package density including theantenna. In some embodiments the antenna can be fitted in a rectangulararea, the longest edge of which is shorter than one-twentieth of thelongest free-space operating wavelength of the antenna. Alternatively,the arrangement of the package in terms of layout, antenna and chiparrangement allows the whole package to be smaller than one-twentieth ofthe free-space operating wavelength.

One aspect of the present invention is the box-counting dimension of thecurve that forms at least a portion of the antenna. For a given geometrylying on a surface, the box-counting dimension is computed in thefollowing way: First a grid with boxes of size L1 is placed over thegeometry, such that the grid completely covers the geometry, and thenumber of boxes N1 that include at least a point of the geometry arecounted; secondly a grid with boxes of size L2 (L2 being smaller thanL1) is also placed over the geometry, such that the grid completelycovers the geometry, and the number of boxes N2 that include at least apoint of the geometry are counted again. The box-counting dimension D isthen computed as:

$D = {- \frac{{\log\left( {N\; 2} \right)} - {\log\left( {N\; 1} \right)}}{{\log\left( {L\; 2} \right)} - {\log\left( {L\; 1} \right)}}}$

In terms of the present invention, the box-counting dimension iscomputed by placing the first and second grids inside the minimumrectangular area enclosing the curve of the antenna and applying theabove algorithm.

The first grid should be chosen such that the rectangular area is meshedin an array of at least 5×5 boxes or cells, and the second grid ischosen such that L2=½L and such that the second grid includes at least10×10 boxes. By the minimum rectangular area it will be understood sucharea wherein there is not an entire row or column on the perimeter ofthe grid that does not contain any piece of the curve. Thus, some of theembodiments of the present invention will feature a box-countingdimension larger than 1.17, and in those applications where the requireddegree of miniaturization is higher, the designs will feature abox-counting dimension ranging from 1.5 up to 3, inclusive. For someembodiments, a curve having a box-counting dimension of about 2 ispreferred. For very small antennas, that fit for example in a rectangleof maximum size equal to one-twentieth of the longest free-spaceoperating wavelength of the antenna, the box-counting dimension will benecessarily computed with a finer grid. In those cases, the first gridwill be taken as a mesh of 10×10 equal cells, while the second grid willbe taken as a mesh of 20×20 equal cells, and then D is computedaccording to the equation above. In the case of small packages with ofplanar designs, i.e., designs where the antenna is arranged in a singlelayer on a package substrate, it is preferred that the dimension of thecurve included in the antenna geometry have a value close to D=2.

In general, for a given resonant frequency of the antenna, the largerthe box-counting dimension the higher the degree of miniaturization thatwill be achieved by the antenna. One way of enhancing theminiaturization capabilities of the antenna according to the presentinvention is to arrange the several segments of the curve of the antennapattern in such a way that the curve intersects at least one point of atleast 14 boxes of the first grid with 5×5 boxes or cells enclosing thecurve. Also, in other embodiments where a high degree of miniaturizationis required, the curve crosses at least one of the boxes twice withinthe 5×5 grid, that is, the curve includes two non-adjacent portionsinside at least one of the cells or boxes of the grid.

An example of how the box-counting dimension is computed according tothe present invention is shown in FIG. 9A and FIG. 9B. An example of acurve 900 according to the present invention is placed under a 5×5 grid901 and under a 10×10 grid 902. As seen in the graph, the curve 900touches N1=25 boxes in grid 901 while it touches N2=78 boxes in grid902. In this case the size of the boxes in grid 901 is twice the size ofthe boxes in 902. By applying the equation above it is found that thebox-counting dimension of curve 902 is, according to the presentinvention, equal to D=1.6415. This example also meets some othercharacteristic aspects of some preferred embodiments within the presentinvention. The curve 900 crosses more than 14 of the 25 boxes in grid901, and also the curve crosses at least one box twice, that is, atleast one box contains two non adjacent segments of the curve. In fact,900 is an example where such a double crossing occurs in 13 boxes out ofthe 25 in 901.

The package arrangements in which the antenna is built on a single layerof a package substrate are very convenient in terms of cost because asingle mask can be used for processing the antenna pattern on such alayer. In some embodiments the antenna is arranged in a single layer andfed in one tip of the curve, such that no conductor crossing over thecurve is required. Although not required, a further simplification andcost reduction is achieved by means of those embodiments in the presentinvention wherein the antenna and the chip are mounted on the same layerof a package substrate.

It is noted that, according to the present invention, the antennastructure is not limited to a planar structure, because the package caninclude several portions or parts of the antenna in multiple layers orcomponents of the package.

In the case of non-planar, multi-layer or volumetric structures for theantenna pattern within the package, the box-counting algorithm can becomputed by means of a three-dimensional grid, using parallelepipedcells instead of rectangular and meshes with 5×5×5 cells and 10×10×10 or20×20×20 cells, respectively. In those cases, such a curve can take adimension larger than two and in some cases, up to three.

FIG. 10 shows an alternative embodiment of the package 2, which hasalready been described in FIG. 2, mounted on a ground plane 1000. In thefigure, it is only represented a portion of the ground plane 1000 in thevicinity of the package 2.

The ground connector GND of the package 2 is connected to the groundplane 1000 by means of connection 1002. The ground plane 1000 is locatedwith respect to the package 2 so as not to be underneath or above the atleast one antenna 100.

In this embodiment the antenna 100 comprises a parasitic element 1001that is located outside the package 2. The parasitic element 1001 isalso connected to the ground plane 1000 by means of connection 1003.

FIG. 11 shows an alternative embodiment of the package 4 of FIG. 4, inwhich the radio-frequency component 450 outside the package 4 is amatching network 1100.

FIG. 12 shows another embodiment of the package 4 of FIG. 4, in whichthe radio-frequency component 450 outside the package 4 is a bypass orthrough-connection 1200. Furthermore, in this embodiment the RF circuit430 comprises a filter 1201.

FIG. 13 shows a further embodiment of the package 4 of FIG. 4, in whichthe radio-frequency component 450 outside the package 4 comprises apower amplifier 1300.

FIG. 14 shows an alternative embodiment of the package 1 of FIG. 1, inwhich the antenna 100 is a modular or discrete component 1400. Inparticular, said modular or discrete component 1400 is a surface mounttechnique (SMT) component.

FIG. 15 shows an embodiment of a package 15 similar to the one alreadydescribed in connection with FIG. 1, but in which an antenna 1500 has aparasitic element 1501 located inside the package 15.

FIG. 16 shows an embodiment of a system comprising the package 4 of FIG.4 and a second antenna 1600 external to the package 4. Theradio-frequency component 450 outside the package 4 comprises a switch1601 that makes it possible to commute between the antenna 100 arrangedin the package 4 and the second antenna 1600, providing antennadiversity.

FIG. 17A shows an embodiment of a system comprising an antenna 1701 andan electrical circuit 1702 enclosed in a common package housing 1710having a form factor of an in-line package for integrated circuitpackages.

FIG. 17B shows an embodiment of a system comprising an antenna 1701 andan electrical circuit 1702 enclosed in a common package housing 1720having a form factor of a surface mount package for integrated circuitpackages.

FIG. 17C shows an embodiment of a system comprising an antenna 1701 andan electrical circuit 1702 enclosed in a common package housing 1730having a form factor of a ball grid array package for integrated circuitpackages.

FIG. 18 shows an embodiment of a system comprising an antenna 1801 andan electrical circuit 1802 enclosed in a common package housing 18having a form factor of a leadframe package for integrated circuitpackages. The package housing 18 comprises a metal layer 1803 on whichthe antenna 1801 has been created and on which the electrical circuit1802 is mounted.

FIG. 19A shows an alternative embodiment of the package 3 of FIG. 3, inwhich the radio-frequency circuit 330 comprises a balun 1901, the balun1901 being a discrete component.

FIG. 19B shows a further embodiment of the package 3 of FIG. 3, in whichthe radio-frequency circuit 330 comprises a balun 1902, the balun 1902being a printed circuit.

FIG. 20 shows an embodiment of multiple-antenna communication system2000 that forms a multiple-input-multiple-output (MIMO) system. Themultiple-antenna communication system 2000 comprises two packages 2001and 2002 (such as the one in FIG. 1) mutually connected through acontrol circuit 2003. The MIMO system 2000 receives signals from threeremote transmitters (2011, 2012 and 2013)

FIG. 21 shows an embodiment of multiple-antenna communication system2100 that forms a smart antenna system. The multiple-antennacommunication system 2100 comprises three packages 2101, 2102 and 2103(such as the one in FIG. 1) mutually connected through an adaptivecontrol circuit 2104. The adaptive control circuit 2104 combines theradiation patterns of the antennas included in the packages 2101-2103 sothat a resulting radiation pattern 2105 can be selectively directedtowards a remote transmitter 2106 and away from a jamming source 2107optimizing the signal-to-interference ratio of the system.

FIG. 22 shows an embodiment of multiple-antenna communication system2200 that forms a phased array system. The multiple-antennacommunication system 2200 comprises three packages 2201, 2202 and 2203(such as the one in FIG. 1) mutually connected through a phase shifter2204. The antennas included in the packages 2201-2203 form an array,each antenna being fed with a phase determined by the phase shifter2204. By modifying the phases applied to the antennas, the tilt angle ofthe radiation pattern 2206 of the array can be varied. Themultiple-antenna communication system 2200 further comprises a controlcircuit 2205 to determine the sequence in which the phases are varied todefine a scanning path.

FIG. 23 shows an embodiment of multiple-antenna communication system2300 that forms a sensor network. The multiple-antenna communicationsystem 2300 comprises four packages 2301, 2302, 2303 and 2304 (such asthe one in FIG. 1) mutually connected through a central controlprocessor 2305.

1. System comprising: an antenna and an electrical circuit, wherein theantenna and the electrical circuit are arranged in an integrated circuitpackage, wherein the antenna comprises a conducting pattern, at least aportion of which includes a curve comprising at least five segments,each of said at least five segments forming a pair of angles with arespective adjacent segment in said curve, at least three of saidsegments being shorter than one-tenth of the longest free-spaceoperating wavelength of said antenna, and wherein said conductingpattern fits inside a rectangular area of the package, a longest side ofsaid rectangular area being shorter than one-fifth of a longestfree-space operating wavelength of said antenna.
 2. System of claim 1,wherein the electrical circuit performs a base-band functionality. 3.System of claim 1, wherein the electrical circuit performs a digitalfunctionality.
 4. System according to claim 1, wherein the electricalcircuit comprises a radio-frequency circuit.
 5. System according toclaim 4, wherein a coupling between the antenna and the radio-frequencycircuit is a reactive coupling.
 6. System according to claim 4, whereinthe system comprises a ground plane, and wherein the radio-frequencycircuit is connected to the ground plane.
 7. System according to claim6, wherein the ground plane is located with respect to the package so asnot to be underneath or above the antenna.
 8. System according to claim4, wherein at least some of the connections of the radio-frequencycircuit are balanced.
 9. System according to claim 4, wherein the systemcomprises a radio-frequency component outside the package, and whereinthe antenna is connected to the radio-frequency circuit and at least apart of the radio-frequency circuit is connected to the radio-frequencycomponent outside the package.
 10. System according to claim 4, whereinthe system comprises a radio-frequency component outside the package,and wherein the antenna is connected to the radio-frequency componentoutside the package.
 11. System according to claim 4, wherein theradio-frequency circuit comprises a balun.
 12. System according to claim11, wherein the balun is a printed circuit.
 13. System according toclaim 11, wherein the balun is a discrete component.
 14. Systemaccording to claim 4, wherein the package comprises a radio-frequencyinput/output connector, and wherein at least one of the antenna and theradio-frequency circuit comprises a connection with the radio-frequencyinput/output connector.
 15. System according to claim 4, wherein thesystem comprises a radio-frequency component outside the package andwherein at least one of the radio-frequency circuit and theradio-frequency component outside the package includes at least onefilter.
 16. System according to claim 1, comprising a radio-frequencycomponent outside the package.
 17. System according to claim 16, whereinthe radio-frequency component outside the package is a matching network.18. System according to claim 16, wherein radio-frequency componentoutside the package is at least one of a bypass or a through-connection.19. System according to claim 16, wherein the radio-frequency componentoutside the package comprises a power amplifier.
 20. System according toclaim 1, wherein the antenna is connected to an input/output connectorof the package and at least a part of the electrical circuit isconnected to the input/output connector of the package.
 21. Systemaccording to claim 1, wherein the antenna is a space filling antenna.22. System according to claim 21, wherein the space-filling antenna hasa dimension larger than 1 when computed as a grid dimension calculation.23. System according to claim 21, wherein the space-filling antenna hasa dimension larger than 1 when computed as a box counting dimensioncalculation.
 24. System according to claim 1, wherein, for each pair ofangles, the smaller angle of the pair is less than 180° and at least twoof said smaller angles are less than 115°, wherein at least two of theangles, which are on the same side of the curve and are formed fromadjacent segments of the group of said at least five segments, aredifferent.
 25. System according to claim 24, wherein at least two of theangles, which are on the same side of the curve and are formed fromadjacent segments of the group of said at least five segments, aredifferent.
 26. System according to claim 1, wherein the antenna is amodular or a discrete component.
 27. System according to claim 26,wherein the modular or discrete component is a surface mount technique(SMT) component.
 28. System according to claim 1, wherein the antennacomprises two ends, and wherein both ends of the antenna are connectedto the package.
 29. System according to claim 28, wherein at least oneend of the two ends of the antenna is connected to an input/outputconnector of the package.
 30. System according to claim 28, wherein bothends of the antenna are connected to input/output connectors of thepackage.
 31. System according to claim 1, wherein the antenna has aparasitic element.
 32. System according to claim 31, wherein theparasitic element is inside the package.
 33. System according to claim31, wherein the parasitic element is outside the package.
 34. Systemaccording to claim 1, comprising a second antenna external to thepackage.
 35. System according to claim 34, wherein the system comprisesa switch that commutes between the antenna and the second antenna. 36.System according to claim 35, wherein the switch is provided outside thepackage.
 37. System according to claim 35, wherein the switch isprovided on the package.
 38. System according to claim 35, wherein theswitch that commutes between the antenna and the second antenna providesan antenna diversity system.
 39. System according to claim 1, whereinthe antenna is disabled.
 40. System according to claim 1, wherein theantenna is a balanced antenna.
 41. System according to claim 1, whereinthe antenna is an unbalanced antenna.
 42. System according to claim 1,wherein the antenna is loaded with discrete reactive components. 43.System according to claim 42, wherein the antenna is loaded withexternal loads.
 44. Multiple-antenna communication system comprising aplurality of mutually connected systems, wherein each system of theplurality of mutually connected systems comprises: an antenna and anelectrical circuit, wherein the antenna and the electrical circuit arearranged in an integrated circuit package, wherein the antenna comprisesa conducting pattern, at least a portion of which includes a curvecomprising at least five segments, each of said at least five segmentsforming a pair of angles with a respective adjacent segment in saidcurve, at least three of said segments being shorter than one-tenth ofthe longest free-space operating wavelength of said antenna, and whereinsaid conducting pattern fits inside a rectangular area of the package, alongest side of said rectangular area being shorter than one-fifth of alongest free-space operating wavelength of said antenna.
 45. Systemaccording to claim 44, wherein the multiple antenna communication systemis one of a multiple-input-multiple-output system, a smart antennasystem, a phased array system and a sensor network.
 46. A system,comprising: an antenna formed on a substrate, the antenna comprising amulti-segment conductor provided in a space-filling pattern, at least aportion of which including a curve comprising at least five segments,each of said at least five segments forming a pair of angles with arespective adjacent segment in said curve, at least three of saidsegments being shorter than one-tenth of the longest free-spaceoperating wavelength of the antenna, the antenna occupying a rectangulararea of the substrate in which a longest side of the rectangular area isshorter than ⅕ of a longest free space operating wavelength of theantenna, and a circuit also provided on the substrate, wherein theantenna and the circuit are enclosed in a common package housing. 47.The system of claim 46, wherein the package housing is an integratedcircuit package.
 48. The system of claim 47, wherein the package housingis a surface mount package.
 49. The system of claim 47, wherein thepackage housing is a ball grid array package.
 50. The system of claim47, wherein the package housing is an in-line package.
 51. The system ofclaim 47, wherein the package housing is a leadframe package.
 52. Systemcomprising: at least one antenna and an electrical circuit, wherein theelectrical circuit comprises a radio-frequency circuit, wherein the atleast one antenna and the electrical circuit are arranged in a package,said package being an integrated circuit package, wherein the systemfurther comprises a radio-frequency component outside the package, andwherein the at least one antenna is connected to the radio-frequencycomponent outside the package.